drm/i915: kill ranged cpu read domain support

	/** Record of address bit 17 of each page at last unbind. */

	unsigned long *bit_17;

	/**

	 * If present, while GEM_DOMAIN_CPU is in the read domain this array

	 * flags which individual pages are valid.

	 */

	uint8_t *page_cpu_valid;

	/** User space pin count and filp owning the pin */

	uint32_t user_pin_count;

	struct drm_file *pin_filp;

static __must_check int i915_gem_object_flush_gpu_write_domain(struct drm_i915_gem_object *obj);

static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj);

static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj);

static __must_check int i915_gem_object_set_cpu_read_domain_range(struct drm_i915_gem_object *obj,

								  uint64_t offset,

								  uint64_t size);

static void i915_gem_object_set_to_full_cpu_read_domain(struct drm_i915_gem_object *obj);

static __must_check int i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,

						    unsigned alignment,

						    bool map_and_fenceable);

	i915_gem_object_flush_gtt_write_domain(obj);

	/* If we have a partially-valid cache of the object in the CPU,

	 * finish invalidating it and free the per-page flags.

	 */

	i915_gem_object_set_to_full_cpu_read_domain(obj);

	old_write_domain = obj->base.write_domain;

	old_read_domains = obj->base.read_domains;

	return 0;

}

/**

 * Moves the object from a partially CPU read to a full one.

 *

 * Note that this only resolves i915_gem_object_set_cpu_read_domain_range(),

 * and doesn't handle transitioning from !(read_domains & I915_GEM_DOMAIN_CPU).

 */

static void

i915_gem_object_set_to_full_cpu_read_domain(struct drm_i915_gem_object *obj)

{

	if (!obj->page_cpu_valid)

		return;

	/* If we're partially in the CPU read domain, finish moving it in.

	 */

	if (obj->base.read_domains & I915_GEM_DOMAIN_CPU) {

		int i;

		for (i = 0; i <= (obj->base.size - 1) / PAGE_SIZE; i++) {

			if (obj->page_cpu_valid[i])

				continue;

			drm_clflush_pages(obj->pages + i, 1);

		}

	}

	/* Free the page_cpu_valid mappings which are now stale, whether

	 * or not we've got I915_GEM_DOMAIN_CPU.

	 */

	kfree(obj->page_cpu_valid);

	obj->page_cpu_valid = NULL;

}

/**

 * Set the CPU read domain on a range of the object.

 *

 * The object ends up with I915_GEM_DOMAIN_CPU in its read flags although it's

 * not entirely valid.  The page_cpu_valid member of the object flags which

 * pages have been flushed, and will be respected by

 * i915_gem_object_set_to_cpu_domain() if it's called on to get a valid mapping

 * of the whole object.

 *

 * This function returns when the move is complete, including waiting on

 * flushes to occur.

 */

static int

i915_gem_object_set_cpu_read_domain_range(struct drm_i915_gem_object *obj,

					  uint64_t offset, uint64_t size)

{

	uint32_t old_read_domains;

	int i, ret;

	if (offset == 0 && size == obj->base.size)

		return i915_gem_object_set_to_cpu_domain(obj, 0);

	ret = i915_gem_object_flush_gpu_write_domain(obj);

	if (ret)

		return ret;

	ret = i915_gem_object_wait_rendering(obj);

	if (ret)

		return ret;

	i915_gem_object_flush_gtt_write_domain(obj);

	/* If we're already fully in the CPU read domain, we're done. */

	if (obj->page_cpu_valid == NULL &&

	    (obj->base.read_domains & I915_GEM_DOMAIN_CPU) != 0)

		return 0;

	/* Otherwise, create/clear the per-page CPU read domain flag if we're

	 * newly adding I915_GEM_DOMAIN_CPU

	 */

	if (obj->page_cpu_valid == NULL) {

		obj->page_cpu_valid = kzalloc(obj->base.size / PAGE_SIZE,

					      GFP_KERNEL);

		if (obj->page_cpu_valid == NULL)

			return -ENOMEM;

	} else if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0)

		memset(obj->page_cpu_valid, 0, obj->base.size / PAGE_SIZE);

	/* Flush the cache on any pages that are still invalid from the CPU's

	 * perspective.

	 */

	for (i = offset / PAGE_SIZE; i <= (offset + size - 1) / PAGE_SIZE;

	     i++) {

		if (obj->page_cpu_valid[i])

			continue;

		drm_clflush_pages(obj->pages + i, 1);

		obj->page_cpu_valid[i] = 1;

	}

	/* It should now be out of any other write domains, and we can update

	 * the domain values for our changes.

	 */

	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);

	old_read_domains = obj->base.read_domains;

	obj->base.read_domains |= I915_GEM_DOMAIN_CPU;

	trace_i915_gem_object_change_domain(obj,

					    old_read_domains,

					    obj->base.write_domain);

	return 0;

}

/* Throttle our rendering by waiting until the ring has completed our requests

 * emitted over 20 msec ago.

 *

	drm_gem_object_release(&obj->base);

	i915_gem_info_remove_obj(dev_priv, obj->base.size);

	kfree(obj->page_cpu_valid);

	kfree(obj->bit_17);

	kfree(obj);

}